1. Field of the Invention
The present invention relates to cameras.
More particularly, but not exclusively, the invention relates to a camera of the instant-picture (self-developing) type.
2. The Prior Art
Cameras of the self-developing type, with reference to which the invention will herein be explained by way of example, use film cassettes (film packs) wherein several individual film sheets are contained in a cassette housing. After an exposure has been made, the just exposed film sheet must be moved out of the cassette housing and transported to the exterior of the camera. During such transportation a developer substance contained in a pouch of the film sheet must be spread over the picture area to develop the latent image.
Various types of drives have been proposed for the film transporting mechanism of such cameras. This includes electric motors, cranks which must be turned by hand and slidable input members which slide parallel to the direction of film transportation and transmit motion to a gear train.
Slidable input members have various advantages which makes their use desirable. For example, they can serve certain auxiliary functions, such as to cover (and protect) a viewfinder of the camera when the input member is in its inoperative position. However, from a practical point of view these prior-art input members are not well suited for use in cameras in which the film sheet (developed picture) is expelled through an outlet at the top or the bottom (as compared to the sides or back) of the camera. The movement of these prior-art input members is parallel to the direction of film transportation, as observed above; hence, in a camera having a top or bottom outlet such movement would have to be in upward or downward direction. This is a difficult movement to impart to the input member (by hand) when, as is always the case in instant-picture cameras, a substantial amount of force must be applied to the input member (to move the film sheet through the nip between a pair of rollers which serve to transport the film sheet as well as to squeeze the developer from its pouch and spread it over the exposure area of the film sheet).
To overcome this problem it has been proposed to make the input member slidable in parallelism with the optical axis. This permits the user to exert much greater force upon the input member. However, there is a general trend in many types of cameras (especially the so-called "pocket" cameras) to use slidable input members which are movable in a generally horizontal direction transverse to the optical axis. In these "pocket" cameras this presents no problem, because the film transport takes place in the same direction. To be consistent for different types of cameras it is desirable to have the same (transverse) direction of the slidable input member also in instant-picture cameras, especially as the "pocket" camera experience shows that users prefer it. Unfortunately, this is not readily possible in instant-picture cameras in which the direction of film transportation is normal to such a direction of movement of the input member, i.e., in cameras having top or bottom picture outlets.